FAQ:

Fedora:
 Why can't I playing some YouTube videos (HTML5 error) and where can I get the codecs to run H.264 videos?   Solution

 How to configure a fresher look for your GRUB2 at Fedora instead of the black white one:   Click here

General (CentOS, Fedora, Ubuntu, Debian, Manjaro, ...):
 Kernel panic error (sync fail) at various distributions when starting the installation.   Solution